(a) The solid will stay afloat only if its entire weight is balanced by the force of buoyancy. Thus, solid exerts a force equal to its weight.

(b) The force of buoyancy is equal to the weight of the solid immersed in the liquid.

(c) From the Archimedes principle, the force of buoyancy is equal to weight of the liquid displaced which is in turn equal to the weight of the immersed solid. Hence, option (C) is true while option (D) is not.